Database terms
Where your data lives, breathes, and occasionally panics
Almost every application is, at its core, a system for reading and writing data. This category covers relational and non-relational databases, query optimisation, indexing strategies, transactions, normalisation, replication, and the CAP theorem trade-offs that dictate how distributed data behaves. Choosing and using the right database correctly is one of the highest-leverage skills in backend development.
InnoDB vs MyISAM
InnoDB is the default MySQL storage engine supporting transactions, foreign keys, and row-level locking — MyISAM is legacy with table-level locking and no transaction support.
1mo ago
database beginner
MySQL AUTO_INCREMENT
A column attribute that automatically assigns sequential integer IDs on INSERT — the standard primary key pattern in MySQL.
1mo ago
database beginner
MySQL Date and Time Types
DATETIME, TIMESTAMP, DATE, TIME, and YEAR — each with different ranges, timezone handling, and storage sizes.
1mo ago
database beginner
MySQL ENUM Type
A column that accepts only predefined string values — stored efficiently as integers but with significant schema change pain.
1mo ago
database beginner
MySQL JOIN Types
INNER JOIN, LEFT JOIN, RIGHT JOIN, and CROSS JOIN — controlling which rows are included when combining tables.
1mo ago
database beginner
MySQL NULL Handling
NULL in SQL represents an unknown value — it is not zero, not empty string, and comparisons with = NULL are always false.
1mo ago
database beginner
MySQL Numeric Types
INT, BIGINT, DECIMAL, FLOAT, DOUBLE — the right type prevents overflow, precision loss, and money calculation bugs.
1mo ago
database beginner
MySQL String Types: VARCHAR vs TEXT vs CHAR
CHAR is fixed-length, VARCHAR is variable-length up to 65,535 bytes, TEXT variants store large content — each with different indexing and storage behaviour.
1mo ago
database beginner
ORM — Object-Relational Mapper PHP 7.0+
A library that maps database rows to PHP objects and vice versa — handling SQL generation, relationships, and lazy loading, at the cost of hiding query behaviour that can cause N+1 problems if used carelessly.
2mo ago
database beginner